From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Alexis Berlemont <alexis.berlemont@gmail.com>
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
mingo@redhat.com, alexander.shishkin@linux.intel.com,
hemant@linux.vnet.ibm.com
Subject: Re: [PATCH v2 1/2] perf sdt: add scanning of sdt probles arguments
Date: Fri, 25 Nov 2016 11:40:02 -0300 [thread overview]
Message-ID: <20161125144002.GC16426@kernel.org> (raw)
In-Reply-To: <20161118235637.21651-2-alexis.berlemont@gmail.com>
Em Sat, Nov 19, 2016 at 12:56:36AM +0100, Alexis Berlemont escreveu:
> During a "perf buildid-cache --add" command, the section
> ".note.stapsdt" of the "added" binary is scanned in order to list the
> available SDT markers available in a binary. The parts containing the
> probes arguments were left unscanned.
>
> The whole section is now parsed; the probe arguments are extracted for
> later use.
>
> Signed-off-by: Alexis Berlemont <alexis.berlemont@gmail.com>
> ---
> tools/perf/util/symbol-elf.c | 16 +++++++++++++++-
> tools/perf/util/symbol.h | 1 +
> 2 files changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> index 99400b0..0fbe0b2 100644
> --- a/tools/perf/util/symbol-elf.c
> +++ b/tools/perf/util/symbol-elf.c
> @@ -1822,7 +1822,7 @@ void kcore_extract__delete(struct kcore_extract *kce)
> static int populate_sdt_note(Elf **elf, const char *data, size_t len,
> struct list_head *sdt_notes)
> {
> - const char *provider, *name;
> + const char *provider, *name, *args;
> struct sdt_note *tmp = NULL;
> GElf_Ehdr ehdr;
> GElf_Addr base_off = 0;
> @@ -1881,6 +1881,20 @@ static int populate_sdt_note(Elf **elf, const char *data, size_t len,
> goto out_free_prov;
> }
>
> + args = (const char *)memchr(name, '\0', data + len - name);
Humm, no need for casting?
> +
> + /*
> + * There is no argument if:
> + * - We reached the end of the note;
> + * - There is not enough room to hold a potential string;
> + * - The argument string is empty or just contains ':'.
> + */
> + if (args == NULL || data + len - args < 2 ||
> + args[1] == ':' || args[1] == '\0')
> + tmp->args = NULL;
> + else
> + tmp->args = strdup(++args);
Shouldn't we check this and do error back propagation? I.e. if there are
args and we don't handle them, silently, that looks bad
> +
> if (gelf_getclass(*elf) == ELFCLASS32) {
> memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
> tmp->bit32 = true;
> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
> index 2d0a905..913be07 100644
> --- a/tools/perf/util/symbol.h
> +++ b/tools/perf/util/symbol.h
> @@ -347,6 +347,7 @@ int arch__choose_best_symbol(struct symbol *syma, struct symbol *symb);
> struct sdt_note {
> char *name; /* name of the note*/
> char *provider; /* provider name */
> + char *args;
> bool bit32; /* whether the location is 32 bits? */
> union { /* location, base and semaphore addrs */
> Elf64_Addr a64[3];
> --
> 2.10.2
next prev parent reply other threads:[~2016-11-25 14:40 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-16 23:55 [PATCH 0/2] perf: add support of SDT probes arguments Alexis Berlemont
2016-11-16 23:56 ` [PATCH 1/2] perf sdt: add scanning of sdt probles arguments Alexis Berlemont
2016-11-16 23:56 ` [PATCH 2/2] perf probe: add sdt probes arguments into the uprobe cmd string Alexis Berlemont
2016-11-17 9:04 ` Hemant Kumar
2016-11-18 23:56 ` [PATCH v2 0/2] " Alexis Berlemont
2016-11-18 23:56 ` [PATCH v2 1/2] perf sdt: add scanning of sdt probles arguments Alexis Berlemont
2016-11-25 14:40 ` Arnaldo Carvalho de Melo [this message]
2016-11-26 0:58 ` [PATCH v4 0/2] perf probe: add sdt probes arguments into the uprobe cmd string Alexis Berlemont
2016-12-05 23:42 ` Alexis Berlemont
2016-12-06 14:45 ` Arnaldo Carvalho de Melo
2016-11-26 0:58 ` [PATCH v4 1/2] perf sdt: add scanning of sdt probles arguments Alexis Berlemont
2016-12-07 2:44 ` Masami Hiramatsu
2016-11-26 0:58 ` [PATCH v4 2/2] perf probe: add sdt probes arguments into the uprobe cmd string Alexis Berlemont
2016-12-07 3:26 ` Masami Hiramatsu
2016-12-09 15:14 ` Arnaldo Carvalho de Melo
2016-12-10 10:00 ` Masami Hiramatsu
2016-12-14 0:07 ` [PATCH v5 0/2] " Alexis Berlemont
2016-12-14 7:36 ` Ingo Molnar
2017-01-23 11:23 ` Ravi Bangoria
2017-02-22 22:41 ` Alexis Berlemont
2017-01-24 6:58 ` Ravi Bangoria
2017-01-24 8:22 ` Ingo Molnar
2017-01-24 8:36 ` Ravi Bangoria
2017-02-02 11:11 ` [PATCH 0/5] perf/sdt: Argument support for x86 and powepc Ravi Bangoria
2017-02-02 11:11 ` [PATCH 1/5] perf/sdt: Show proper hint Ravi Bangoria
2017-02-02 13:40 ` Ingo Molnar
2017-02-02 16:20 ` Arnaldo Carvalho de Melo
2017-02-03 10:26 ` [PATCH v2] " Ravi Bangoria
2017-02-03 15:18 ` Arnaldo Carvalho de Melo
2017-02-07 7:53 ` Ingo Molnar
2017-02-07 15:50 ` Arnaldo Carvalho de Melo
2017-02-07 8:00 ` Ingo Molnar
2017-02-16 10:16 ` [RFC] perf/sdt: Directly record SDT event with 'perf record' Ravi Bangoria
2017-02-20 7:08 ` Ingo Molnar
2017-02-20 8:21 ` Ravi Bangoria
2017-02-20 8:42 ` Ingo Molnar
2017-02-20 11:01 ` Ravi Bangoria
2017-02-20 14:11 ` Arnaldo Carvalho de Melo
2017-02-23 8:13 ` Ravi Bangoria
2017-02-23 12:48 ` Arnaldo Carvalho de Melo
2017-02-07 1:13 ` [PATCH v2] perf/sdt: Show proper hint Masami Hiramatsu
2017-02-10 7:44 ` [tip:perf/core] perf sdt: Show proper hint when event not yet in place via 'perf probe' tip-bot for Ravi Bangoria
2017-02-02 11:11 ` [PATCH 2/5] perf/sdt/x86: Add renaming logic for rNN and other registers Ravi Bangoria
2017-02-07 3:11 ` Masami Hiramatsu
2017-03-21 14:08 ` Arnaldo Carvalho de Melo
2017-03-24 18:45 ` [tip:perf/core] perf sdt x86: " tip-bot for Ravi Bangoria
2017-02-02 11:11 ` [PATCH 3/5] perf/sdt/x86: Move OP parser to tools/perf/arch/x86/ Ravi Bangoria
2017-02-07 3:11 ` Masami Hiramatsu
2017-02-07 5:22 ` Ravi Bangoria
2017-03-21 14:10 ` Arnaldo Carvalho de Melo
2017-03-21 23:00 ` Masami Hiramatsu
2017-03-22 11:22 ` Arnaldo Carvalho de Melo
2017-03-21 14:55 ` Masami Hiramatsu
2017-02-02 11:11 ` [PATCH 4/5] perf/sdt/powerpc: Add argument support Ravi Bangoria
2017-02-02 11:11 ` [PATCH 5/5] perf/probe: Change MAX_CMDLEN Ravi Bangoria
2017-02-07 1:40 ` Masami Hiramatsu
2017-02-07 5:45 ` [PATCH v2] " Ravi Bangoria
2017-03-21 5:19 ` Masami Hiramatsu
2017-03-21 13:37 ` Arnaldo Carvalho de Melo
2017-03-24 18:43 ` [tip:perf/core] perf probe: " tip-bot for Ravi Bangoria
2017-02-07 2:55 ` [PATCH 0/5] perf/sdt: Argument support for x86 and powepc Masami Hiramatsu
2017-03-06 7:53 ` Ravi Bangoria
2017-03-06 13:42 ` Masami Hiramatsu
2017-03-21 5:08 ` [PATCH v5 0/2] perf probe: add sdt probes arguments into the uprobe cmd string Masami Hiramatsu
2016-12-14 0:07 ` [PATCH v5 1/2] perf sdt: add scanning of sdt probles arguments Alexis Berlemont
2017-03-06 13:39 ` Masami Hiramatsu
2017-03-21 13:52 ` Arnaldo Carvalho de Melo
2017-03-24 18:44 ` [tip:perf/core] perf sdt: Add scanning of sdt probes arguments tip-bot for Alexis Berlemont
2016-12-14 0:07 ` [PATCH v5 2/2] perf probe: add sdt probes arguments into the uprobe cmd string Alexis Berlemont
2017-01-24 8:50 ` Ravi Bangoria
2017-03-06 17:23 ` Masami Hiramatsu
2017-03-24 18:44 ` [tip:perf/core] perf probe: Add " tip-bot for Alexis Berlemont
2016-11-18 23:56 ` [PATCH v2 2/2] perf probe: add " Alexis Berlemont
2016-11-21 10:25 ` Hemant Kumar
2016-11-24 23:13 ` [PATCH v3 0/2] " Alexis Berlemont
2016-11-24 23:13 ` [PATCH v3 1/2] perf sdt: add scanning of sdt probles arguments Alexis Berlemont
2016-11-24 23:13 ` [PATCH v3 2/2] perf probe: add sdt probes arguments into the uprobe cmd string Alexis Berlemont
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